Who Knew
by WishUponAnIdiot
Summary: Highschool AU based off the song by Pink: Dean and Cas didn't have a perfect relationship, but no one did in high school. They were two best friends that loved each other more than anyone understood, but they were broken apart by a single promise.


**Warnings:** High school Au, mentions of Castiel/Balthazar, angst, fluff, watch your step you might become a sobbing mess.

_I wish I could touch you again_  
><em>I wish I could still call you a friend<em>  
><em>I'd give anything<em>

_When someone said count your blessings now_  
><em>For they're long gone<em>

* * *

><p>"Get a room!" Sam called out, passing Dean and Cas in the crowded school hallway. Dean gripped harder on Castiel's hand, smiling down at him and looking back just in time to scowl at his brother. Cas chuckled, pulling on Dean's hand turning them down a different hallway. This one was mostly empty, and as the hallway cleared, Cas cleared his throat, turning to face Dean.<p>

Dean leaned down, kissing Cas quickly, stepping back to watch as Cas turned into his classroom, a grin spreading out from being beneath Dean's lips. Cas' cheeks went red as someone in the class wolf-whistled as he strode in, and he looked back at Dean, the teen grinning wickedly before leaving down the hallway.

By the time Cas went to leave the classroom, Dean was halfway there, wrapping an arm around Cas' shoulder, as Cas wrapped an arm around Dean's waist and they walked down the hallway with soft smiles on their faces.

* * *

><p>Dean smiled, fingers lacing with Castiel's, as he backed them against the brick wall of the school. He leaned down, capturing Cas' lips with his own. Cas smiled into the kiss, loving how Dean gripped his hands tighter, placing them against the brick wall above his head. They only had a few minutes before heading back to their class, but for now, they just let their tongue's battle. Each graze, each touch, a promise.<p>

A promise that no matter what, they would be together like this for the rest of their lives.

Cas listened to each promise in his mind, his heart hammering in his chest.

* * *

><p>"You and your fuck buddy are never gonna last." Someone whispered to the pair as they walked down the almost empty hallway. Dean turned around, unable to recognize whomever it was.<p>

"Excuse me, douche-bag?" Dean questioned, Cas grabbing his arm to move them toward their next class.

"I said, you and your fuck buddy aren't going to even remember each other when you grow up. Stop pretending like you two are gonna grow old together. You're gonna have your gross gay sex, and come college, you're both gonna realize how much pussy you each want." The student responded, a twisted grin on his face as he spoke.

Cas did his best to hold Dean back, but he knew he wouldn't be able to. Dean punched the poor bastard in the face, his nose cracking beneath Dean's fist.

The day ended with a week long suspension, but whenever Cas mentioned it, Dean just grinned and whispered 'worth it'. That night, he spent hours kissing promises of forever into Cas' skin.

* * *

><p>"Cas, what the hell are you doing?" Dean asked, sitting himself next to his boyfriend, who was squinting up at the morning sky as they waited outside for the first bell to ring.<p>

"Staring at the sun." Cas replied, as if it was the most normal thing in the world. Dean chuckled, carding his fingers through Cas' hair.

"You'll go blind if you do that too much." Dean stated, turning Cas' face to greet his own. Cas closed his eyes quickly as they shared a chaste kiss.

"Then I will have you as my guide."

* * *

><p>Dean kicked lightly at Cas' shin beneath the table, the pair sitting across from each other at lunch. Cas looked over from his conversation with Anna, before giving a swift kick back. He grinned at the small wince Dean gave him in return.<p>

When the pair left the crowded cafeteria, the two jokingly tried to kick each other in the ass. Cas managed a light tap to Dean's, and ran down the hall, Dean right behind him. They practically crashed into each other, laughter and running making them out of breath.

Dean breathed heavily, before pressing his lips gently to Cas'. "Meet you by the car?" Dean asked, knowing that Cas would always meet him there at the end of every day, but still liked asking, if only for Cas' response.

Cas smiled as he made his way down the hall, turning around and yelling "Always."

* * *

><p>Cas yawned softly, rolling over to greet Dean with a smile as the pair lay on the firm bed. The two of them had decided to take a small nap after several hours of studying, and Cas grinned at the clock on the wall, seeing that dinner would be very soon. He sat up on the bed, hand laying flat against Dean's chest. They stayed like that for a while, the pair smiling at each other as they steadily grew more alert.<p>

"Hey, Cas?"

"Yeah, Dean?"

Dean sighed, sitting up on the bed, trying to gather his words properly. This wasn't exactly an easy subject. "I..I think I want to enlist." Dean finished, his heart hammering loudly, his fingers shaking. It was something he'd been thinking about for months, something he could never really bring himself to mention. But he was tired of keeping it hidden, and wanted to see how Cas would feel about it.

Cas turned to face him, fear shaking through him. "Enlist? Enlist where?" Cas asked, worry spreading through him like disease, easing into his bones. He knew exactly what Dean meant, but every part of his brain wanted to think otherwise.

"The Army." Dean stated quickly, his hands reaching for Castiel's, only for Cas to flinch away from them. Dean sighed softly before explaining further. "I think it'd be good for me, Cas. God knows, I don't have any kind of life here. It'd be better to enlist now, that way I can be out right as summer finishes."

"No." Cas stated, his hands firmly gripping the fabric beneath him.

"Cas."

"No, Dean." Cas stated again, turning to look Dean in the eye, his hands gripping harder on the thin fabric. "You have a life here, Dean. I'm staying local for college, you could find one too, get a job, stay with Sam." Cas could feel his voice shaking as he spoke, but tried his best to keep his tears in.

"That's not a life, Cas! I would never be good at college, and getting some shitty job just to be with you and Sam, that's not living, Cas." Dean finished, grabbing Cas face beneath his hands. "I love you, Cas. I don't want to hurt you."

Cas sighed heavily before leaning in for a kiss, his eyes wet with tears but he managed to keep them at bay. "I love you too. Just...please promise me, you won't do this, Dean." Cas pleaded, his hand releasing the bed sheet to graze his thumb beneath Dean's eye.

"Cas..." Dean started but Cas' glare shut him up.

"Please, Dean." Dean stared into blue eyes, shiny with tears, and void of happiness. Dean finally gave a small nod before leaning to capture Cas' lips. Dean spent that night whispering 'I'm sorry' between each kiss, more gentle than he'd been in a while. Almost as gentle as their first night like this. Cas took it as making-up, not knowing what Dean had planned.

When Dean finished school the next day, he called his recruiting officer on his way out to the car. That weekend he went to their offices, and filed the necessary paperwork, answered the necessary questions, did the necessary physical and signed himself up to fly out at the end of August.

Come September he'd be gone.

* * *

><p>Dean and Cas studied for finals together in Dean's room, surprisingly enough, they both managed good grades, despite that whenever they chose to study, they'd get distracted by the other. Chaste kisses above note sheets quickly became heavy breaths and swift movements on top of worn sheets.<p>

Dean smiled proudly when he showed Cas' his grades the day before graduation, all of them a B- or above. Cas had kissed him softly, whispering soft praises, saying over and over how he knew that Dean would do well.

Graduation itself wasn't too big of a deal. Dean thought that with all the hype it managed to get, that it'd be more dramatic. Reality was, that you heard your name, walked across a small stage with a piece of paper, and shook a few hands.

Afterwards John and Sam had taken Dean out to dinner, Cas and his older brother Gabriel tagging along. The restaurant they picked had almost kicked them out, Dean and Gabriel being loud and lively, John trying to keep them quiet, and Sam had spent the entire evening talking to Sam about what college courses he should take to prepare him.

By the time Dean fell asleep that night, the realization that he only had a little over two months left finally settled in.

* * *

><p>Summer for Dean and Cas, meant night's at Ash' place, almost twenty people gathered in the old park behind his yard, two big tents propped up on the grass. Ash would have one every few weeks, and they always had fun lighting campfires, telling stupid stories, walking around empty streets at night, having little adventure's and making up jokes.<p>

Tonight was no different and Dean watched as Cas was laying on a small blanket, staring up at the sky while he talked to Anna. Dean was settled by the small fire near the river, Chuck and Ash talking to him about college babes. Ash was headed for M.I.T., Chuck was going to the same school as Cas, they even planned to carpool together when they could.

None of them knew that Dean was leaving soon.

* * *

><p>Cas stretched out on the small couch, his body lengthening like a cat as he yawned loudly before scratching at the bit of tummy exposed from his stretch. Dean chuckled down at him, practically throwing the bowl of popcorn at him while he reached for the remote on the table.<p>

Dean doesn't remember anymore what movie was playing. All he remembers is, Cas deciding to hit him with little pieces of popcorn, laughing every time he managed to get one down Dean's open neck shirt.

After that, Dean spent the next five minutes shoving handfuls down the back of Cas' shirt, the popcorn leaving behind a messing trail of butter and salt.

He spent the next hour, kissing and licking away the taste of popcorn from Cas' skin.

* * *

><p>"Dean, come stretch with me." Cas pleaded, reaching out and grabbing Dean's hand. "Dean did his best to remain seated, sending up a glare at Cas.<p>

"I'm not doing any of that yoga shit you enjoy." Dean replied, finally coming to stand up from his spot on the bed.

"It's not yoga, Dean. Just a bit or morning stretching. It's good for you." Cas stated, coming to sit down on the open floor, seated a few feet from where Dean still stood. "Sit, and just follow whatever I do." Dean gave Cas a skeptical look, but when Cas pat the small area of carpet floor for Dean to sit on, Dean finally complied.

Dean watched as Cas stretched his arm out in front of him, using his other arm to pull it to his chest. Dean mimicked the action, pouting as he didn't really see the point in any of this.

By the time they got to stretching out their legs, Dean was starting to feel more relaxed, and he chuckled at the look of satisfaction on Castiel's face. Cas bent over, his hands reaching the bottom of his feet, a little piece of skin showing as Cas' shirt rode up his back. Instead of mimicking the action, Dean leaned his body towards Cas, tickling the small area with tongue.

Cas was about to protest,leaning back up when Dean moved quickly, straddling him on the carpet floor. "What do you know, I feel looser already." Dean stated before leaning down to kiss along Cas' jaw.

Needless to say, the two of them spent the day warm and relaxed.

* * *

><p>"Dean, I think we need to talk." Cas started one day, surprising Dean. Dean looked at him with wide eyes, wondering if maybe Cas had found out about him actually enlisting. "I already have everything set for college and a part time job once September rolls around, what are you going to do?" Cas asked, and Dean sighed heavily, a small smile gracing his lips.<p>

"I got it covered." Dean replied, leaning forward to grab Cas' face in his hands, laying a soft kiss on Cas' lips. Cas looked unconvinced, but trusted Dean enough to believe him.

The sad part was, Dean wasn't lying. Cas cursed himself every time he remembered that afternoon. He wished that he had been more forceful on the subject. Maybe things would have been different.

* * *

><p>When August came around, a few of the old high school jocks decided to throw a huge pool party. Dean dragged Cas along with him, knowing that it wasn't really his kind of thing, but he didn't want to go alone. Plus if Cas was there with him, he wouldn't drink any of the alcohol.<p>

After thirty minutes of dancing in the living room, music blaring loudly throughout the whole house, Cas dragged him outside and over to the pool. The area was pretty empty considering, mostly littered with a few drunken teenagers, and some people making out. Dean playfully shoved Cas, but grabbed onto his arm at the last second to keep him from falling in the pool.

Cas glared at him, before doing the same, except when he went to grab Dean's arm he missed and Dean fell in, water splashing upwards. Cas watched horrified, ready to dive in if Dean didn't resurface. Dean's head popped out of the water, quite a few people watching with shocked looks on their faces. Dean scowled up at Cas, watching the horror change to relief in Cas' eyes. He pushed up, climbing out of the pool, grinning down at Cas before wrapping his arms around him and jumping into the pool, soaking them both.

Dean resurfaced quickly, grinning wildly as Cas glared daggers between wet hair covering his eyes. "Ass." Cas finally let out, splashing water at Dean's face. Dean splashed back, moving closer to Cas.

"Yeah, but you love me."

* * *

><p>Dean chuckled softly, his chin resting on Cas' shoulder. Cas was going on about some random actor that did a good job in some movie, 'Tom' Dean thought to himself. Cas' mouth only closed mid syllable as he kept going on and on about them.<p>

Dean wrapped his arms around Cas' waist tighter, turning his head to blow in Cas' ear. Cas shot a glare at him but before Cas could calculate some kind of attack, Dean bit down on his neck, licking the soft part right below his ear, before pulling on the small bit of flesh with his teeth.

Cas groaned as Dean continued his nibbling, waiting until Dean's mouth had moved from his skin before pushing him towards the end of the bed. As Dean went to sit back up on the bed, Cas continued from his last sentence, going on for another twenty minutes before Dean finally distracted him.

* * *

><p>Before Dean knew where time had gone, August was coming to a close. Cas was going to start up freshman orientation in three days and Dean was going to leave in two. Now came, how to tell Cas. Everything was telling him, that he had fucked up, that he shouldn't have done it, that he should have told Cas months ago, but he just wanted to stay with Cas, as long as he could.<p>

He didn't want this to end. He was leaving in two days, and for the first time since he had started thinking about it, he was afraid.

Not about fighting the war, not about protecting his country. His only fear was that, when Cas found out, he'd hate Dean. Dean always hated when he was right.

* * *

><p>"YOU FUCKING BASTARD!" Cas yelled at the top of his lungs, his body shaking with anger. "You fucking promised me, that you wouldn't do it!" Cas continued, tears leaking down his eyes as he spoke. Dean could count the number of times he had heard Castiel yell. He could even count the amount of times he had heard him swear on the same hand, and still have a few fingers left.<p>

To hear Cas swear at him like this, it was the worst thing he'd ever heard. Cas and Dean weren't perfect, no couple was, but their bickering was never this serious, never about Dean _leaving. _Dean never wanted to hear Cas yell for the rest of his life.

"I know. I'm not condoning what I did, Cas. I lied, and of anything in my life, I regret not telling you about what I did. But I don't regret enlisting, at all." Dean whispered, trying to wrap his arms around Cas. Cas swatted him away, turning to walk down the street. "Cas, please. I don't want our last memory of each other before I leave to be of us fighting."

"Maybe you shouldn't have signed up for the fucking army!"

"I'm doing what's right, Cas. I have nothing here! I'm leaving tomorrow and we're just going to have to deal with that!"

Cas laughed wickedly, his voice filled with anger, though he'd lowered his tone considerably. "Maybe you will, but I'm not."

Dean froze, his face contorted into confusion and fear. His hands dropped to his sides, swaying slightly. "Cas, you don't mean that."

"The hell I don't." Cas bit back, arms crossed as he stared Dean down. "I am not, going to sit around, and wait for you to come back. I'm not going to wait for an email knowing you're okay, wait for a god damn letter saying you're missing, or waiting for you to be lowered into the ground. I can't do that." Cas finished, tears streaming harder down his eyes.

"Cas..."

"Don't. I don't care. No matter what job you have there, there is still the chance of you coming home in a body bag. No, I won't. I can't. I'm done, Dean. Best of luck dodging bullets." Dean watched Cas turn and leave, his body collapsing onto the ground as his friend of eight years, boyfriend of two, walked away from him.

When he'd told Sammy, that he was joining the military, Sam had given him a sad but proud face and wished him luck. When he'd told John, his father had given him a proud smile, and patted him on the shoulder.

When Dean Winchester told Castiel about going to the military, Cas had left with hate filled words and tears running down his face.

* * *

><p>Dean left the next day, off to boot camp. Cas spent the next day alone in his room, wanting so badly to run to Dean, and apologize, but knowing that he couldn't, that Dean was gone by now. He prepared himself for college, and he read every book he could find, anything to distract his mind.<p>

Dean woke up every morning, a faded memory of Cas passing his mind, of hands wrapped around his waist, of Cas and Sam making pancakes for him on his birthday, of Gabriel sneaking into the room and waking the two up with a fire alarm.

Cas woke up every morning, a faded memory of Dean doing the same. Of Dean holding his hand as they walked down the hallway, the smile he made every time he turned the engine of his beautiful car, of Dean teasing him and Sam whenever they talked about classes or novels.

For months, it was hard. Dean struggled with boot camp but in the end, he was one of the best recruits they had. Cas almost failed a few of his classes, but he managed to pick his grades up in time for the end of term.

Slowly, the want to see Dean, slowly turned into resentment. He was so angry, and it was Dean's fault. He expected Dean to stay in town, get a small job and be able to see him at least every few days. He didn't expect months without contact, of every night trying to fall asleep with their yelling match playing through his head.

All he wanted was to sleep in Dean's arms again.

* * *

><p>Half a year from their last bit of talking, and they had both started to move on. Dean was settling in nicely, boot camp finally being over. A lot of the weapons training had proved his affinity for guns, as well as being a fairly decent sniper.<p>

Cas had moved on in his own way. He'd gained a few friends at the school, was even dating an art major named Balthazar.

Sometimes Cas would see Sam, ask how Dean was doing knowing the two emailed each other. Sam never said anything, but Dean would ask about Castiel as well.

Everyday the two of them woke up, and went to bed, the other on their mind, but even still they kept going.

* * *

><p>Two and a half years after their last sighting, June rolled around, high school graduation coming close. Cas decided to go, knowing that Sam would be graduating, along with his girlfriend Jessica, and a few other old high school friends he had. Balthazar had offered to come with him, but he didn't really know anyone here, so he'd denied the offer.<p>

He didn't expect to walk up before the ceremony, and find Dean several rows in front of him, full military uniform, with Dean's father situated next to him.

He almost turned tail and ran, but Sam's eyes met his, and he knew he couldn't leave, so he sat down further back, waiting and watching the ceremony unfold.

When everything was over, Cas waited to hug the few friends that had graduated, only to almost walk straight into Dean. He stood still, giving an awkward smile as he stood a few feet from Dean. Dean smiled back the same way, unsure of what to do with his hands. "Hey, Cas."

"Hi, Dean." Cas replied quickly, his awkward smile fading slightly.

"You look good." Dean finally stated, staring up into Cas' eyes with such a strange familiarity, it was as if three years hadn't even happened. Cas stared back, the awkward smile from before transforming into one of adoration, his eyes glossy.

"You too, Dean." Cas responded, his hands stuffed into his pockets, twitching as he resisted the urge to run forward and throw his arms around Dean.

Neither of them did anything, just looked into each other's eyes with anger,love, resentment, and so many other emotions, that they didn't know what to do, but stare. Words just seemed awkward. It wasn't until Sam walked over, saying hi to Cas before mentioning to Dean about their dinner plans. Dean gave one last look to Cas, watching as Cas waved his hand slowly as goodbye.

Neither of them knew that would be the last they ever saw of each other.

* * *

><p>After a few months of civilian life, Dean decided to go back, and he volunteered himself for another tour. Cas molded back into college life, Balthazar helping in whatever way he can.<p>

Balthazar was great to him, and after a few drinks one night, Cas had let slip about everything that happened with him and Dean, and Balthy showed no anger at all, when he talked to Cas about it the next day. He seemed perfectly fine with everything, and as much as Cas hated it, that's exactly what he needed. Balthazar was never Dean's replacement, nothing Cas could ever have would compare.

Years went by, and they both managed to move on with their lives completely.

But every single day, Dean thought about Cas; and every day Cas did the same. The two of them only had a few regrets in their life. They each wished that their two last moments together had played out so different. It was funny how those regrets, were exactly the same for the both of them.

People say that, teen love isn't real, it's just hormones and infatuation. But Dean and Castiel knew differently. They had met as boys, grew up as friends, and became lovers; and every single day, they thought about each other, kept each other looked in their minds.

Who knew that one broken promise, could be the end of something so beautiful.


End file.
